Correlation between Salt Concentration and Electricity
by Chris L, Sam W, and Pari
Variables:
Independent Variable
Salt Concentration in the Water Dependent Variable
The Electrical Current/ Voltage
Hypothesis:
Chris:
A positive correlation between salt concentration and current/voltage Sam:
The voltage will rise the less amount of salt added.
Equipment:
Water
Salt
Copper piece
Iron piece
Tape
Two alligator clipped connection wires
Multi-Meter
Beaker
Stirrer
Electrical Balance
Procedure:
Fill a beaker with 250g of pure water.
Secure a piece of copper and a piece of iron against the two opposite sides of the beaker.
Measure the current and voltage with a multi-meter.
Stir 2 grams of salt into water.
Measure current and voltage again.
Repeat step 4-5 until 20g of salt in total have been added.
Record and process data.
DATA 1:
Amount of Salt in 250g of water (g)
Concentration of Salt (%)
Voltage (Volts)
Current (Amperes)
0
0
0.53
0.150
2
0.8
0.45
0.070
4
1.6
0.35
0.030
6
2.3
0.30
0.020
8
3.1
0.25
0.020
10
3.8
0.25
0.020
12
4.6
0.32
0.015
14
5.3
0.30
0.015
16
6.0
0.25
0.015
18
6.7
0.25
0.015
20
7.4
0.25
0.015
My hypothesis was that as the salt concentration rises, the voltage and current would also rise. However, according to the chart and the graph that follows, my apposition is visibly wrong. Our table and graph shows that as the salt concentration rises, the voltage and current decreases, and water by itself has the highest ability to insulate. This was against what should be true according to reliable sources so we decided to redo our experiment and do it the other way round: instead of adding salt each time to gain concentration, we would dilute the solution each time to decrease the concentration
Procedure2:
Pour 50g of the solution out.
Measure current.
Pour 100g out and 100g of pure water in to dilute the solution by half.
Measure current.
Repeat step 3-4 until solution's purity has reached 1/64
Record and process data.
DATA 2:
Solution Purity* (%)
Concentration of Salt (%)
Current (Amperes)
100
7.4
0.1
50
3.2
0.11
25
1.6
0.09
12.5
0.8
0.07
7.25
0.4
0.06
3.625
0.2
0.05
1.8125
0.1
?
*=Pure in this case refers to a solution of 7.4% salt in 200g of water =During this last measure I tried to place to iron in a more secure position and when it touched the glass, the amperes nearly double! This time we started seeing what I hoped to see, a positive trend. When the Concentration of salt decreased, the current also decreased. But as I was stabilizing the iron piece, we realized that whenever the water stirs by even the smallest bit, the current will change. More noticeable was whenever the iron touched the glass; the current would increase up to twice as high!
Evaluation and Conclusion
What we can assume to be true: Now we are quite sure that salt promotes insulation water based on our second experiment. Doubts we have: Although we assume there is a positive correlation between salt concentration and current, we are not a hundred percent sure because of the unexplainable reactions such as how stirring and touching of glass affects current, and the first experiment we conducted.
Modifications
There are some possible modifications to further investigate the unaccounted variables that prevented us from reaching a definite conclusion such as the follows: l Conduct an experiment to find the relationship between the distance of the two metal pieces and the current. l Conduct an experiment to find the relationship between the amount of stirring and the current (using a stirrer). l Further research leading to experiments that can better determine the effect touching glass has on the current. l Finally if we have understood all the points above, we can create a better controlled experiment that can tell us the correlation between salt concentration and electricity.
Table of Contents
Correlation between Salt Concentration and Electricity
by Chris L, Sam W, and PariVariables:
Independent VariableSalt Concentration in the Water
Dependent Variable
The Electrical Current/ Voltage
Hypothesis:
Chris:A positive correlation between salt concentration and current/voltage
Sam:
The voltage will rise the less amount of salt added.
Equipment:
Procedure:
DATA 1:
Procedure2:
DATA 2:
=During this last measure I tried to place to iron in a more secure position and when it touched the glass, the amperes nearly double!
This time we started seeing what I hoped to see, a positive trend. When the Concentration of salt decreased, the current also decreased. But as I was stabilizing the iron piece, we realized that whenever the water stirs by even the smallest bit, the current will change. More noticeable was whenever the iron touched the glass; the current would increase up to twice as high!
Evaluation and Conclusion
What we can assume to be true:Now we are quite sure that salt promotes insulation water based on our second experiment.
Doubts we have:
Although we assume there is a positive correlation between salt concentration and current, we are not a hundred percent sure because of the unexplainable reactions such as how stirring and touching of glass affects current, and the first experiment we conducted.
Modifications
There are some possible modifications to further investigate the unaccounted variables that prevented us from reaching a definite conclusion such as the follows:l Conduct an experiment to find the relationship between the distance of the two metal pieces and the current.
l Conduct an experiment to find the relationship between the amount of stirring and the current (using a stirrer).
l Further research leading to experiments that can better determine the effect touching glass has on the current.
l Finally if we have understood all the points above, we can create a better controlled experiment that can tell us the correlation between salt concentration and electricity.